x1, y1, x2, y2 = map(float, input().split())
print('%.8f' % (((x2 - x1)**2 + (y2 - y1)**2))**0.5) x1, y1, x2, y2 = map(float, input().split()) x1 map(float, input().split()) map float input().split() ().split () input split y1 x2 y2 print('%.8f' % (((x2 - x1)**2 + (y2 - y1)**2))**0.5) print '%.8f' % (((x2 - x1)**2 + (y2 - y1)**2))**0.5 '%.8f' (((x2 - x1)**2 + (y2 - y1)**2))**0.5 (x2 - x1)**2 + (y2 - y1)**2 (x2 - x1)**2 x2 - x1 x2 x1 2 (y2 - y1)**2 y2 - y1 y2 y1 2 0.5 y1, x2, y2 = map(float, input().split()) map(float, input().split()) y1 x1, y1, x2, y2 = map(float, input().split()) map(float, input().split()) x1 x2, y2 = map(float, input().split()) map(float, input().split()) x2 y2 = map(float, input().split()) map(float, input().split()) y2
x1, y1, x2, y2 = map(float, input().split())
print('%.8f' % (((x2 - x1)**2 + (y2 - y1)**2))**0.5)
